1. Field of the Invention
The present invention relates to an image display device, and more particularly, to an image display device which comprises an antiglare surface having unevenness and pixels having a pixel pitch of about 10 to about 100 xcexcm.
2. Description of the Related Art
With regard to image display devices, density of displayed image has recently increased year by year even in a small image display device having a small display area. For example, as for small image display devices having a display screen of 2.5 inch size, image display devices having 180,000 or more pixels have been developed as well as conventional ones having about 80,000 pixels. As for image display devices performing a color display, a pixel pitch (a) of image display devices having about 180,000 pixels is about 60 xcexcm, while the pixel pitch (a) of image display devices having about 80,000 pixels is generally about 80 to about 100 xcexcm. Here, a pixel pitch (a) is a distance between adjacent pixels and refers to the minimum one of the longitudinal and lateral dimensions of individual pixels forming an image. In the case of image display devices performing a color display, the pixel pitch (a) represents the minimum one of the longitudinal and lateral dimensions (a and b) of individual pixels (7R, 7G and 7B) that respectively indicate R(red), G(green), or B(blue) (See, FIG. 1).
On the other hand, an image display device which has an antiglare surface having unevenness on the utmost surface thereof has been known for preventing the surrounding scenery from showing up in the screen thereof. An image display device possessing such an antiglare surface has advantages in that visibility of displayed images is good since the surrounding scenery showing up on the utmost surface thereof is diffused and reflected by the unevenness of the utmost surface, and is not recognized as an image.
However, when the antiglare surface having unevenness is disposed on the utmost surface in an image display device having a pixel pitch (a) of smaller than about 100 xcexcm, a so-called xe2x80x9cglittering (scintillation)xe2x80x9d is generated in some cases, thereby sometimes leading to decrease in clearness of images. Such xe2x80x9cglitteringxe2x80x9d lowers the visibility of displayed images.
The inventors of the present invention have devoted intensive efforts to restrain the xe2x80x9cglitteringxe2x80x9d generated in image display devices which comprises an antiglare surface having unevenness and pixels having a pixel pitch (a) of smaller than about 100 xcexcm. As a result, the inventors of the present invention have found that in image display devices which comprises pixels having such a pixel pitch (a), the generation of xe2x80x9cglitteringxe2x80x9d can be restrained when a ratio of an average spacing of roughness peak (Sm) of the unevenness on the antiglare surface to the pixel pitch (a) is a specific value or smaller. Thus the inventors have accomplished the present invention.
The present invention provides an image display device which comprises an antiglare surface having unevenness and pixels having a minimum pixel pitch (a) of from about 10 to about 100 xcexcm, wherein a ratio (Sm/a) of an average spacing of roughness peak (Sm) of the unevenness to the minimum pixel pitch (a) is about 0.4 or smaller.